Simplify the expression. $ (-z^{7}-3z^{5}+5z^{4}) + (-7z^{4}-7z^{3} ) $
Since we are adding polynomials, we can simply remove the parentheses. $-z^{7}-3z^{5}+5z^{4} - 7z^{4}-7z^{3}$ Identify like terms. $ - { z^7} - \color{#DF0030}{3 z^5} + {5 z^4} - {7 z^4} - \color{#9D38BD}{7 z^3} $ Combine like terms. $ { -1 z^7} + \color{#DF0030}{ -3 z^5} + { z^4} + \color{#9D38BD}{ -7 z^3} $ Add the coefficients. $-z^{7}-3z^{5}-2z^{4}-7z^{3}$